1. Field of the Invention
The subject invention generally relates to seat assembly having a seating surface with a zone which is temperature controlled, and more specifically, with the heating element disposed in the zone along a predetermined path for providing electrical heating of variable temperature along the predetermined path to the zone.
2. Description of Related Art
Nearly every vehicle today has a seat assembly with a seating surface having a seat back and a seat bottom. Often, the seat back and seat bottom each have a zone which is temperature controlled. A heating element conventionally is disposed along a winding path within the zone for providing electrical heating to the zone. The heating element includes typically one or more heating strands which are electrically conductive. A power source is connected to the heating element for energizing the heating strands such that the heating element generates electrical heating to the zone. Each heating strand has a consistent cross-section throughout the winding path. In addition, the heating element conventionally has a consistent number of heating strands along the winding path such that the heating element provides electrical heating uniformly along the winding path. In other words, the heating element provides a consistent temperature along any point throughout the winding path. In effect, conventional heating elements consume a consistent amount of power per unit length, i.e., per meter.
However, conventional heating elements have a variety of disadvantages. First, conventional heating elements consume a large amount of power. Since conventional heating elements consume a consistent amount of power per unit length, power consumption is maximized along the winding path of the heating element. Second, conventional heating elements can frequently provide discomfort to an occupant of the seat assembly. Between winding portions of the heating element are regions of the seating surface which are less exposed to electrical heating. Conventional heating elements concentrate the electrical heating substantially along the winding path as opposed to the regions of the seating surface between winding portions of the heating element. Therefore, those regions of the seating surface which are less exposed to electrical heating are often cooler than surrounding areas thereby causing a temperature differential, or temperature gap in the region. The occupant senses the temperature gap on the seating surface which, in effect, causes discomfort to the occupant.
Therefore, there remains an opportunity to develop a seat assembly that has a heating element disposed in the zone for providing electrical heating of variable temperature at various points along a predetermined path. In addition, there remains an opportunity to develop a seat assembly that has a heating element which consumes less power than conventional heating elements. Furthermore, there remains an opportunity to develop a seat assembly that has a heating element which avoids causing discomfort to an occupant of the seat assembly by minimizing temperature gaps on the seating surface.